WASHING METHOD AND COMPOSITION

Abstract: It is disclosed a process for cleaning vehicles, especially cars, with an alkaline washing composition, preferably comprising one or more surfactants, where the washing composition is sprayed onto the vehicle with one or more nozzles or foam generators and where the alkaline washing composition in connection with the spraying onto the vehicle is combined with an aqueous solution of a cellulose derivative forming a semi-stable composition with congeals and absorbs/adsorbs the dirt particles removing them from the surface when the composition is rinsed off. It is preferred to add fibers in the rinsing water when hosing the composition off or in the cleaning solutions, and it is also preferred to perform the process at a pressure, e.g. 1-150 bars. The two components forming the cleaning composition are preferably combined by using an ejector system operated with water for obtaining the relevant concentrations of each component. The fiber dispersion may also be used separately with conventional washing compositions.

Description: WASHING METHOD AND COMPOSITION The present invention presents an improved system and composition for washing dirty surfaces, and which is especially developed for washing vehicles. It is previously known numerous types of washing compo¬ sitions to be used when washing e.g. vehicles, but all of these compositions are meant to be used together with either manual washing or with rotating brushes or hanging cloth which mecanically remove dust and dirt from the surface. Such manual or mechanical washing is, however, abrasive on the surface and may in many cases destroy the finish or the paint on the vehicle. Previously it has also been attempted to hose off the layer of dust from the surfaces of the vehicle, but it has been found that the layer of dust adhers so strongly that spraying or hosing even at high pressure has not been satisfactory even with the addition of known washing soultions. According to the present invention it has surprisingly been found that a composition comprising a mixture of a water- soluble cellulose derivative, such as a hydroxyl cellulose derivative, e.g. ethyl hydroxy cellulose, in a neutral to alkaline aqueous dispersion mixed with an alkaline deter¬ gent, will form an agglomerate when it is added to the surface which is to be rinsed, and which partially adsorbs and partially absorbs the dirt particles so that they no longer adher to the surface and easily may be hosed off together with the agglomerate. This saves to a large degree the surface and represents a significant improvement of the cleaning result compared with the previously known washing compositions. The need to clean vehicles without any mechanical treatment has increased, and has been the basis for attempts to find solutions to this problem the last 10 years by using different kinds of compositions and systems. The common factor for all these compositons is that the surface does not become fully clean on account of a fine layer which will often remain and which is not being removed by high pressure spraying in combination with a cleaning compo¬ sition without using strong compositions which will have negative effects on the surface of the vehicle, and will also represent a negative effect on the environment and corrode the car. Many manufacturers have attempted to use acids and/or alkaline solutions and also combinations thereof, but the side effects with corrosion both on the car itself and also on sewer systems etc.. The new effect of the present washing solution and system is that it is made more viscous in the foaming process and that it is preferably supplied with non-abrasive fiber particles in the rinsing/hosing process substituting the mechanical work being necessary in the previous car-washing systems as mentioned supra. The surprising effect of the cleaning solution and process according to the present invention is that each of the cellulose derivative solution and the alkaline solution are readily water-soluble, but corresponding concentrations of stem solutions mixed directly with each other are not soluble. Thus a one-component system with these two stem solutions is not possible, and the two stem solutions enter a temporary semi-stable condition when mixed with water in a container/feeding tank immediately prior to its intro¬ duction into the foam generator, from which the combined foam may be sprayed onto the surface which is to be cleand, and whereupon the compositon is congealing absorbing and adsorbing all the dirt particles onto which it is applied. On account of the limited stability of the washing composi¬ tion according to the invention, only a quantity large enough to clean one or a small number of vehicles or cars is made continuously as needed, and the foaming process increases the volume of the solution to such a degree that the pre-made quantity is enough to clean the vehicle. In 5 this connection a quantity of 2-10 1 premade non-foamed * cleaning solution according to the invention will cover an ordinary vehicle/car when expanded as a foam, and the volume of such a foam may be increased 3-8 times. After a dwell time of 30-60 sec. the dirt is then absorbed/adsorbed 10 into the solution. When hosing off the cleaning solution and dirt from the surface of the vehicle, it is preferred that fibers are introduced in the rinsing water (see infra) , and it is also 15 preferred that this is done at a pressure ranging from 1 to 150 bar. The aqueous dispersion of the hydroxy cellulose derivative added a neutral to alkaline solution of a conventional 20 washing composition gives better washing properties. When using conventional washing compositons together with the cellulose derivative according to the present invention, it has been found that there is achieved a synergistic effect when mixing the cellulose derivative and the alkaline 25 washing composition according to the invention, which increases the cleaning effect of the end product signifi¬ cantly compared to each of the components used alone. Furthermore it has been found that combining the cellulose derivative with the conventional alkaline solution at 30 concentrations which should make them mutually un-mixable, and introducing such a composition through a foam genera¬ tor, preferably at high pressure, to the surface which is w to be cleaned, there is produced a semi-stable compositon which after a time congeals to a gel-like substance which • 35 removes the dust and dirt and leaves the surface clean without any form of abrasive treatment. Below the invention will be more closely disclosed with reference to embodiment examples and also with reference to the figures where Fig. 1 shows one embodiment of the system and process according to the invention, and Fig. 2 shows another and further developed embodiment of the system and process according to the invention. In those cases where there is referred to percentages in the disclosure, unless otherwise specified, this refers to percentages per volume. To produce a washing composition according to the present invention there may e.g. initially be made two stem solu¬ tions comprising the cellulose derivative in the first solution (solution B) which is basic (pH 7-14, preferably 9) and may contain a small amount of the washing solution (1-5%) . The concentration of the cellulose derivative in the aqueous dispersion B lies preferably within the inter¬ val 0 - 10%, more preferred 0 - 5%, e.g. 2% by weight. As an example of the cellulose derivative there may be men¬ tioned "Bermocoll E (230 - 481)", which represents diffe- rent degrees of ethyl-hydroxyethyl cellulose, but also other types of cellulose derivatives will be obvious to the person skilled in the art after having read the present disclosure. Solution A is added to solution/dispersion B as an alkaline aqueous solution with a pH within the interval 7 - 14, e.g. 9. This solution may be merely an aqueous alkaline solut¬ ion with a pH within the above indicated interval, but it is preferred to use a neutral to alkaline washing solution on account of the above mentioned preferred content of surfactants. The use of a suitable washing composition will be obvious to a person skilled in the art since this may only be of a type being conventionally suited for the relevant type of washing. As an example it may be en- tioned that for the washing of vehicles there may be used a stem solution such as "Forvask Vinter" (a liquid alkaline washing and cleaning composition containing White Spirit, complexing agents, surfactants, derivatives of glycol and water) , "Micro" (a liquid tixotropic, alkaline washing and cleaning agent containing High Flash White Spirit, ethyl- enediamine tetraacetic acid natrium salt, surfactants and water) , "Maskin Shampoo" (a liquid alkaline washing compo¬ sition containing surfactants, ethyldiglycol, complexing agents, silicates and water) , "Super Cleaner" (a liquid alkaline washing composition containing surfactants, complexing agents, silicates and water) , all being ob- tainable from Thor Marcus Kjemiske A/S. These washing compositions are of a liquid type, but also solid water- soluble washing agents may of course also be used. The solution A and the solution B will be separately supplied as aqueous stem concentrates and are mixed in the system as mentioned supra into the preferred end solution by adding the water. Thus stem concentrate B may be present in a mixture ratio between water and the cellulose derivative within the interval 1:5 to 1:100, e.g. 1:50, most preferred 1:20. Stem concentrate A may be adjusted according to the circum¬ stances based on the knowledge of the person skilled in the art, since the composition or the use thereof will not differ from the conventional use when adding solution B, but the effect of the combined washing composition will, on account of the above mentioned synergistic washing effect, be significantly improved. Stem concentrate A may, all the same, when using the above mentioned stem concentrate "Forvask Vinter", have a mixture ratio between the stem concentrate and water of 1:10 - 1:100, e.g. 1:50, but may in extreme cases also be used undiluted. By using this two-component system no mechanical touch is needed before rinsing/hosing as described. As an example stem concentrate B (2) (20% aqueous solution) and stem concentrate A (1) (50% aqueous solution, pH=9,0) are made separately. These two concentrates are ejected through individual pipes/hoses/lines (a,b) in quantities of 750 ml/min for concentrate A and 250 ml/min for concentrate B, respectively, and are combined by joining the pipes/hos¬ es/lines into a common line (4) , preferably by using a water-based ejector system wherein the individual pipes (a,b) are combined upstream of a narrowing of a water- leading ejector pipe (c) , and are sucked up by an ejector effect into the water-leading pipe into the feeding tank (5) . The quantity of water flowing in the water-leading pipe (c) may in this example be 5,7 1/min. It will be possible to regulate the mixing conditions being specified supra by using adjustable nozzles/valves on each separate pipe, and the mixing may be stopped by using a stop valve 10 on the ejector pipe (c) . From here it is possible to spray the combined solutions directly onto the surface which is to be cleaned, but it is preferred to let the combined solution made ready for use, pass to a feeding tank (3) . The feeding tank (3) holds just enough solution for a few washing operations. From the feeding tank (3) the solution made ready for use may be sucked via a pump (5) , preferably at high pressure, to an air-adding foam- forming apparatus (6) such as a foam generator, and is sprayed onto the vehicle or the surface (8) which is to be cleaned. The solution according to the invention will thereby form a layer of foam (9) on the vehicle, which after a short while (0,5 - 5 min) will agglomerate, sur¬ round, incorporate and "lift" the dust and dirt particles on the surface up and into the foam. Additionally the cellulose derivative in this system will run together to form a gel-like substance which, when hosed off, will draw and pull and remove dust and dirt particles from the surface which is to be cleaned. When considering very dirty conditions, the solution may be made further effective by incorporating or using a small amount of non-abrasive fiber particles. The fiber material may be dispersed in the water (D, see fig. 2) or e.g. in the cellulose derivative and/or the alkaline washing solution mentioned supra in a container and be pumped into 5 the foam mixture or the foam-forming preparation 6 by a « pump 11 being operated when needed or directly into the rinse-water. By-pass from the pump or a mixing device keeps the mixture in dispersion. The added fiber material will adsorb the miniscule particles having a strong affini- 10 ty to the surface, and lead these into the gel-like mass from the foam. Then the surface may be easily hosed clean, preferably by using a water jet mixed with fibers at high pressure. The solution in the container D may in many cases substitute for the injection from container B. 15 An alternative, and preferred way to use the fiber dis¬ persion is, however, to spray a dispersion of the fibers separately onto the surface which is to be cleaned, after adding the foam. The foam composition according to the 20 present invention should be allowed a dwell time on the surface, e.g. 0,5 - 5 min, before rinsing with water in which fiber preferably is injected, and this procedure will further enhance the cleaning effect of the foam cleaning solution. The fibers are non-abrasive and will have the 25 effect of a soft paper tissue. Optionally the fiber sol¬ ution/dispersion may be made by using a detergent in the dipersing liquid for further enhancing the cleaning effect. For the improved washing system and procedure according to 30 the present invention, there may be used ground or unground fibers, and such fibers may e.g. be obtained by conven¬ tional fiber processes producing an optimal freeness. Thus ' the pulp material being used may e.g. be sulphite pulp, sulphate pulp, thermomechanical pulp, ground wood, se i- ' 35 chemical pulp, etc. Examples of such pulp material which may be used in the present invention may be leaf wood sulphate pulp (e.g. "Tofte EUC (ECF)") or needle wood sulphate pulp (e.g. "Tofte 90 (ECF)"). An examplary and preferred pulp type may be "Folia CTMP 100/60" mechanical wood pulp, but corresponding wood pulp types may also be used, as mentioned supra. The length of the fiber particles may be varied within wide limits. They may have a conventional fiber length and may e.g. lie within the interval 0,5 mm - 5,0 mm. Very minor amounts of added fiber material in the rinsing composition according to the present invention is necessary to achieve the wanted effect, but the volume of added fiber is not critical, so that larger quantities may also be tolerated and even preferred. The concentration of the fibers in the fiber stem solution may be e.g. 0 - 40 g/1, preferably 5 g/1, although this is not critical. The weight of fiber may e.g. be 10 g fiber in a liquid volume of about 2 - 10 1, also being a volume which may be used for washing a conventional private car. It may also be used larger amounts of fibers than the one specified supra, an then the effect is somewhat improved, but the quantity of fiber added in the process must not be so large that it causes blockage of pumps and nozzles. If the nozzles leading the washing solution according to the invention are flushed shortly after the fiber solution/dispersion has passed, it will be avoided that the system is blocked. The fiber particles may easily be filtered in the sewer system together with the adsorbed dirt and thus contribute to a cleaner waste water. The system will in an oil separator function as an oil adsorbing agent, and this will facilitate recirculation of the water. The total effect of the above indicated sequence of events is that when the foam being produced according to the invention is rinsed off from the surface after a dwell time, the surface will be free from dust and dirt particles without the need for mechanical touch of the surface. The aqueous fiber-containing rinsing stem-solution (D) is produced by disperging/mixing the fiber material with water together with surfactants to facilitate the dispersion process of the fibers. The fiber material may also be used separately or in combination with conventional washing solutions for ob¬ taining an improved washing result.

Claims: C l a i s 1. A process for cleaning vehicles, especially cars, with an alkaline washing composition, preferably comprising one or more surfactants, where the washing composition is sprayed onto the vehicle with one or more nozzles, c h a r a c t e r i z e d i n that the alkaline washing composition in connection with the spraying onto the vehicle is combined with an aqueous solution of a cellulose derivative. 2. Process according to claim 1, c h a r a c t e r i z e d i n that the pH of the combined solution is adjusted to lie in the interval 7 - 14, preferably about 9. 3. Process according to claim 1 or 2, c h a r a c t e r i z e d i n that the cellulose derivative is combined with the washing composition at a concentration of the cellulose derivative solution of up to 5 % by weight, preferably 2 % by weight. 4. Process according to any of the preceeding claims, c h a r a c t e r i z e d i n that the cellulose derivative solution and the washing composition solution are combined in a ratio of 1 : 3. 5. Process according to any of the preceeding claims, c h a r a c t e r i z e d i n that the alkaline compo- sition is added to the cellulose derivative solution by using a water ejector, where the washing solution at the combining point is present in a mixing ratio with water of 1:10 - 1:100, e.g. 1:50. 6. Process according to any of the preceeding claims, c h a r a c t e r i z e d i n that the combined sol¬ ution is passed through a foam producing generator before the spraying onto the vehicle. 7. Process according to any of the preceeding claims, c h a r a c t e r i z e d i n that there to one or both of the components and/or to the aqueous phase is added a fiber material. 8. Process according to any of the claims 1 - 6, c h a r a c t e r i z e d i n that the fiber material is added to the rinsing cycle. 9. Process according to claim 8, c h a r a c t e r i z e d i n that the rinsing is performed at pressure, e.g. at 1-150 bar. 10. Process according to any of the claims 7, 8 or 9, c h a r a c t e r i z e d i n that the fiber material has a fiber length of 0,5 - 5,0 mm. 11. Process according to claim 7 - 10, c h a r a c t e r i s e d i n that the fiber material is present in a final concentration of 0-40 g/1, e.g. 5 g/1. 12. Two-component cleaning composition suited for per¬ forming the process according to any of the claims 1 - 11 for cleaning the outer surface of objects, especially vehicles such as cars, wherein one component comprises a per se known neutral to alkaline stem solution, preferably containing one or more surfactants, c h a r a c t e r i z e d i n that the second component of the cleaning composition comprises a cellulose deri¬ vative stem solution having a neutral to alkaline pH-value, wherein the cellulose derivative preferably is present at a concentration of up to 10 % by volume. 13. Two-component cleaning composition according to claim 12, c h a r a c t e r i z e d i n that the pH of the washing solution lies within the interval 7 - 14, prefer¬ ably 9. 14. Two-component cleaning composition according to claim 12 or 13, c h a r a c t e r i z e d i n that the cellulose derivative is present in a concentration of up to 5 % by volume, preferably 2 % by volume. 15. Two-component cleaning composition according to any of the claims 12 - 14, c h a r a c t e r i z e d i n that each of the compo- nents is present as an aqueous solution, where especially the component containing the cellulose derivative is present at a mixture ratio between water and cellulose derivative of 1:5 - 1:100, preferably 1:50, more preferred 1:20. 16. Two-component cleaning composition according to any of the claims 12 - 15, c h a r a c t e r i z e d i n that the mixture ratio between the dispersion containing the cellulose derivative and component containing the alkaline solution is 1 : 1 to 1 : 5, e.g. 1 : 3. 17. Two-component cleaning composition according to any of the claims 12 - 16, c h a r a c t e r i z e d i n that it additionally contains a fiber material. 18. Two-component cleaning composition according to claim 17, c h a r a c t e r i z e d i n that the fiber material has a fiber length within the interval 0,5 - 5,0 mm. 19. Two-component cleaning composition according to any of the claims 15 or 16, c h a r a c t e r i z e d i n that the fiber material is present at a concentration of 0 - 40 g/1, e.g. 5 g/1. 20. Fiber stem solution for performing the rinsing step in the washing process according to claim 7 - 11, c h a r a c t e r i z e d i n that the fiber material is present in an aqueous dispersion at a concentration of 0-40 g/1, optionally in combination with one or more surfactants. 21. Use of a fiber material or fiber stem solution accord¬ ing to claim 20 for cleaning vehicles.

Inventors: MARCUS THOR, MARCUS, THOR
Applicants: MARCUS THOR, THOR MARCUS KJEMISKE AS ING, ING. THOR MARCUS KJEMISKE AS, MARCUS, THOR
Application year: 1994
Main classification: C11D3
IPC codes: B08B3, B60S3, C11D3, C11D11